Tool for safely removing anode lead from cathode ray tube

ABSTRACT

A TOOL FOR SAFELY REMOVING AN ANODE LEAD FROM A CATHODE RAY TUBE SUCH AS A PICTURE TUBE OF A TELEVISION SET. A ROD PORTION OF THE TOOL HAS AN INSULATING HANDLE AT ONE END, A THIN, FLAT, PART WITH A V-SHAPED NOTCH ADJACENT THE OTHER END, AND AN ATTACHED WIRE WITH A SPRING CLAMP AT THE END FOR GROUNDING THE TOOL DURING USE. THE ROD PORTION TERMINATES IN AN ABUTMENT PORTION AT SAID OTHER END. THE FLAT NOTCHED PORTION IS ADAPTED TO SLIDE BENEATH A CUP-LIKE INSULATING COVER PIECE ON THE END OF AN ANODE LEAD SECURED TO THE WALL OF A TV PICTURE TUBE. TWO CONTACT PRONGS EXTEND FROM THE CENTER OF THE COVER PIECE INTO AN APERTURE IN THE TUBE WALL. WHEN THE TOOL IS INSERTED BENEATH THE COVER PIECE, CONVERGING WALLS OF THE NOTCHED PORTION STRADDLE THE PRONGS AND MOVEMENT OF THE TOOL CAMS THE PRONGS TOGETHER TO FACILITATE REMOVAL FROM THE APERTURE. WHERE THE CONTACT IS NOT SUFFICIENTLY ANCHORED TO REQUIRE A CAMMING TOGETHER OF THE CONTACT PRONGS, THE COVER PIECE AND PRONGS CAN BE FORCED FROM THE TUBE WALL BY EXTERNAL PRESSURE APPLIED WITH THE ABUTMENT PORTION OF THE TOOL.

1971 CHOR KEUNG CHANG 3,626,572

TOOL FOR SAFELY REMOVING ANODE LEAD FROM CATHODE RAY TUBE Filed Sept. 19, 1969 mvsm'on;

WM; M 6 m 4 6 N A H C W w e C ATTORNEYS.

United States Patent 3,626,572 TOOL FOR SAFELY REMOVING ANODE LEAD FROM CATHODE RAY TUBE Chor Keung Chang, 19308 Homeway Ave., Cleveland, Ohio 44135 Filed Sept. 19, 1969, Ser. No. 859,322 Int. Cl. H011 3/04 US. Cl. 29-203 H 3 Claims ABSTRACT OF THE DISCLOSURE A tool for safely removing an anode lead from a cathorle ray tube such as a picture tube of a television set. A rod portion of the tool has an insulating handle at one er d, a thin, flat, part with a V-shaped notch adjacent the other end, and an attached wire with a spring clamp at the end for grounding the tool during use. The rod portion terminates in an abutment portion at said other end.

I The flat notched portion is adapted to slide beneath a cup-like insulating cover piece on the end of an anode lead secured to the wall of a TV picture tube. Two contact prongs extend from the center of the cover piece into an aperture in the tube wall. When the tool is inserted beneath the cover piece, converging walls of the notched portion straddle the prongs and movement of the tool cams the prongs together to facilitate removal from the aperture. Where the contact is not sufiiciently anchored to require a camming together of the contact prongs, the cover piece and prongs can be forced from the tube wall by external pressure applied with the abutment portion of the tool.

This invention relates to a tool for safely removing an anode lead from a cathode ray tube such as a television picture tube or the like.

The cathode ray tube or picture tube of a television set is typically mounted on the television set chassis. A high voltage current supply from the chassis is connected to an anode of the tube by an anode lead that typically carries a current of about 25,000 volts or more. Certain picture tubes have a cavity in a side wall portion with an aperture in the outer wall surface of somewhat smaller size than the cavity. The cavity contains an electrical terminal for an anode of the tube and is typically connected to the high voltage supply by a two-pronged contact of the anode lead that is inserted into the cavity. In conventional leads of this type, contact prongs extend from a central inside portion of a vacuum cup that forms an insulating cover over the prongs and aperture and that helps secure the anode lead to the tube. The end of the anode lead is further held in position by the prongs themselves, which typically have oppositely and outwardly directed end portions extending from parallel prong portions that project from the insulating cover. These end portions fit within the cavity, catch under the lip of the aperture, and are retained in laterally spaced apart relationship under the lip by the resiliency of the prongs, which are normally spaced apart a distance as great or slightly greater than the width of the aperture in the tube wall. Whenever there is a disorder that necessitates disconnecting the picture tube, for example, in the replacement of the picture tube, it is necessary to remove the anode lead. This is mechanically diflicult because of the construction described. Also, in some television sets the picture tube and chassis or other parts are so close together that the working space is extremely small. The mechanical difficulty in disconnecting the anode lead is compounded by the care required to avoid an electrical shock, which can be delivered under high voltage even though the set is disconnected from a source of current. The fear of receiving ice an electrical shock results in considerable reluctance on the part of repairmen to change picture tubes and causes them to proceed slowly and with extreme caution, using, for example, a screw driver or the like in an attempt to release one of the prongs and remove the lead.

The present invention comprises a tool that is particularly designed to safely and eifectively remove anode leads of the type described and which is economical to manufacture. Basically, the tool includes an insulating handle portion to facilitate grasping the tool, a rod or shaft portion that extends from the handle, and a relatively thin, substantially flat, prong-compressor portion attached to the rod portion adjacent the end opposite from the handle. The rod portion extends beyond the prong-compressor portion, curving away therefrom, and terminates in a blunt end. A generally V-shaped notch is formed in an edge of the flat prong-compressor portion, opening in a direction away from the handle. Sides of the notch converge inwardly from a lateral spacing greater than the normal spacing between the two prongs of the anode lead to a spacing as small as or smaller than the lateral spacing to which the two prongs must be moved to remove the outwardly directed end portions of the prongs from the cavity in the tube side wall. The fiat prongcompressor portion readily slides between the cup or cover portion at the end of the anode lead and the picture tube side wall, and the notched portion receives the prongs between the converging edges. When the tool is pushed in the direction of the rod portion, the flat prong-compressor portion moves relative to the prongs, and the converging edges of the notched portion cam the prongs together. The prong-compressor portion is then lifted to remove the anode lead from the picture tube. In those instances where the prongs of the anode lead are not caught beneath a lip of the cavity receiving the prongs, the abutment end of the tool can be placed against the cup or insulating cover piece of the anode lead and the cup and prongs can be forced from the tube wall without compressing the prongs. In a preferred embodiment, an electrically conductive wire extends from the rod of the tool and has a clip electrically connected to the wire to conveniently ground the tool during use for example, to the chassis of a television set.

The above features and others of this invention will be come more apparent as the invention becomes better understood by reference to the following detailed description, when considered in connection with the accompanying drawing, in which:

FIG. 1 is a perspective view of the tool of this invention;

FIG. 2 is a perspective view of a television set chassis, showing an anode lead and the manner in which the lead extends from a high voltage source to the television tube side wall;

FIG. 3 is a detailed sectional view taken on line 33 of FIG. 2 through the television tube sidewall and an insulating cup of the anode lead, showing the manner in which a two-pronged contact of the anode lead is received in a cavity in the tube wall;

FIG. 4 is a plan view, with parts broken away, diagrammatically showing the manner in which the tool of FIG. 1 acts to free the prongs of an anode lead from the cavity in the side wall in a television tube; and

FIG. 5 is a transverse sectional view of an insulating cover cup of an anode lead of somewhat different construction from that shown in FIG. 3.

With reference to FIGS. 1 and 2, a tool indicated generally by the reference character 10 embodies the present invention and is used for removing one end 12a of an anode lead 12 from a cathode ray tube such as a picture tube 14 of a television set 16 or the like while the anode lead is connected to a high voltage supply 18. Both the tube and the high voltage supply are carried by a chassis 20 of the television set.

The tool includes an insulating handle portion 22, an elongated rod portion 24, a thin, flat, prong-compressor portion 26 of generally uniform width and thickness, and a ground wire 28 secured to the rod 24 by a screw 29 and terminating in a spring clip 30. The rod portion 24 and prong-compressor portion 26 are typically steel to provide adequate strength and rigidity and due to their conductivity are normally connected to the chassis or other electrical ground during use by the ground wire 28, for safety. In the preferred embodiment shown, the prong-compressor portion is attached adjacent to but spaced from the end of the rod portion 24 remote from the handle, and the rod portion is curved as at 24a beyond the connection to the prong-compressor portion and terminates in a blunt end 24b that can sometimes be used to remove the anode lead from a tube where it is not necessary to compress the prongs. If desired, the prongcompressor portion 26 of the tool can be removable, for example, by providing a slot in the rod portion 24 to receive a back part of the compressor portion 26, an aperture in the portion 26, a tapped hole in the rod aligned with the aperture, and screw for retaining the two parts together. The prong-compressor portion 26 has a V-notch 32 facing away from the handle portion 22. The V-notch is better shown in FIG. 4, and includes two blunt side edges 32a, 32b that converge inwardly from a front or outer end or edge 34. The space between the side edges 32a, 32b at the outer edge 34 is sufficient to receive the spaced prongs of an anode lead, and the side edges converge to an extent that will compress the prongs sufficiently to release them from a receiving aperture of the tube. By way of example, a notch 32 suitable for a typical anode lead is inch wide at the edge 34 and the notch edges 32a, 32b are straight, converge inwardly, and meet at a point inch from the edge 34. The flat portion 26 is typically thinner than A inch to facilitate insertion beneath the edge of a cover cup over the prongs, yet thick enough to maintain rigidity and strength.

One common construction of contacts of an anode lead is shown in FIGS. 3 and 4 of the drawings. In the embodiment shown, the anode lead 12 includes an insulated lead wire 40 that terminates in a resilient suction cup 42 of insulating material, such as rubber or the like. A contact 44 electrically connected with the lead wire 40 has two resilient wire prongs 45, 46 that in use extend from the cup 42 toward the side wall portion 14a of the tube 14. The prongs 45, 46 have foot-like retaining portions 45a, 46a, respectively, that extend outward in opposite directions. The prongs 45, 46 extend through an aperture 50 that opens into a somewhat larger cavity 52 within the wall 14a. The retaining portions 45a, 46a of the prongs make contact with a terminal (not shown) of a tube anode that passesthrough the tube wall and terminates within the cavity 52. The prong retaining portions are held within the cavity 52 by a lip 54 about the aperture 50. In addition, the suction cup 42 aids in retaining the anode lead fixed to the wall 14a of the tube. With the prongs located within the aperture 50 as shown in FIG. 3, they are spaced apart a distance S and are biased apart by the inherent resiliency of the prong construction.

As shown in solid line in FIG. 4, when the prongcompressor portion 26 is inserted between the cup 42 and the tube wall 14a, the space between the edges 32a, 32b of the notch 32 is sufficient to receive the prongs 45, 46. The orientation of the prongs is readily determined by their known relationship to the lead wire 40, which is as shown. Movement of the prong-compressor portion 26 from the position shown in solid line to the position shown in phantom in FIG. 4, as by pushing the handle and rod portions axially of the rod portion toward the pronged contact, compresses the prongs 45, 46 toward each other until the foot-like retaining portions 45a. 46a

have been moved centrally of the aperture 50 a suflicient distance to clear the lip 54. The prongs can then be lifted from the cavity, as by tilting the tool, using the edge 34 as a fulcrum.

A different embodiment of an anode lead is shown at 60 in FIG. 5. In this embodiment, a cup 62 has a contact 65 of somewhat different construction, having two resilient prongs '66, 67 that are substantially wider than they are thick and that terminate in upturned portions 66a, 67a. In some instances, these retaining portions 66a, 67a are not received beneath the lip 50 of the aperture in a tube wall, but rather retain the anode lead by friction against the aperture due to the inherent resilient force tending to spread the prongs apart. In these instances, the.

anode lead can often be removed by merely pushing at one side of the cup 62 with the blunt end or abutment surface 24b of the tool 10. In the event the prongs are retained beneath the lip of an aperture as in the construction described in connection with FIGS. 3 and 4, the prong-compressor portion 26 of the tool is used in the same manner as previously described to compress the prongs 66, 67 together to facilitate removal.

In all instances the clip 30' is attached to a portion of the chassis 20 to effectively ground the rod portion 24 of the tool. i

It will 'be apparent from the above that the present invention provides a tool that will quickly, easily and safely remove anode leads that have heretofore been difficult and dangerous to remove. While a preferred embodiment of this invention has been described in detail, it will be understood that various modifications or alterations may be made therein without departing from the spirit and scope of the invention.

I claim:

1. A tool for removing one end of an anode lead from a cathode ray tube such as the picture tube of a televisiion set or the like while the other end of the lead is connected to a high voltage supply, said one end of the anode lead having a two-pronged contact projecting from an insulating cover piece and adapted to extend through an orifice and be in part received in a cavity somewhat larger than the orifice in the wall of the tube, the two prongs of said contact being generally parallel and resilient, having outwardly oppositely directed retaining portions at the ends and being normally spaced from each other sufliciently to require flexing toward one another to remove the retaining portions from the aperture and cavity, said tool comprising an insulating handle portion to facilitate grasping the tool, a rod portion carried by and extending from the handle, a flexible electrically conductive lead attached to said rod portion and connected therewith for electrical conduction, an electrically conductive spring clip attached and connected for electrical conduction to said lead, and a relatively thin, substantially flat, prong-compressor portion attached to and adjacent the end of said rod portion opposite from the handle portion, said prong-compressor portion having a notch in an edge thereof opening in a direction away from the handle, sides of said notch being blunt and converging in a direction inwardly of said edge from a spacing greater than the spacing between the two prongs of said contact when the contact is located in said orifice to a spacing at least as small as the lateral spacing to which the prongs must be moved to remove the retaining portions of the prongs from the cavity in the tube side wall, whereby the prong-compressor portion can be inserted between the tube wall and the insulating cover piece to receive the prongs of said contact within the notch by movement of the tool axially of the rod portion, with further movement in the same direction the prong-compressor portion will slide relative to the prongs to compress the resilient prongs to a spacing sufficiently close that the retaining portions can pass through the aperture in the tube wall, and with a lifting movement will remove the prongs from the aperture.

2. A tool for removing one end of on anode lead from a cathode ray tube such as the picture tube of a television set or the like while the other end of the lead is connected to a high voltage supply, said one end of the anode lead having a two-pronged contact projecting from an insulating cover piece and adapted to extend through an orifice and be in part received in a cavity somewhat larger than the orifice in the wall of the tube, the two prongs of said contact being generally parallel and resilient, having outwardly oppositely directed retaining portions at the ends and being normally spaced from each other sufliicently to require flexing toward one another to remove the retaining portions from the aperture and cavity, said tool comprising an insulating handle portion to facilitate grasping the tool, a rod portion carried by and extending from the handle, a flexible electrically conductive lead attached to said rod portion and connected therewith for electrical conduction, an electrically conductive spring clip attached and connected for electrical conduction to said lead, a flexible and a relatively thin, substantially flat, prong-compressor portion attached to and adjacent the end of said rod portion opposite from the handle portion, said prongcompressor portion having a V-shaped opening facing in a direction away from the handle, sides of said opening converging inwardly toward the handle from a spacing greater than the spacing between the two prongs of said contact when the contact is located in said orifice to a spacing at least as small as the lateral spacing to which the prongs must be moved to remove the retaining portions of the prongs from the cavity in the tube side wall, whereby the prong-compressor portion can be inserted between the tube wall and the insulating cover piece to receive the prongs of said contact within the V-shaped opening by movement of the tool axially of the rod portion, with further movement in the same direction the prong-compressor portion will slide relative to the prongs to compress the resilient prongs to a spacing sufficiently close that the retaining portions can pass through the aperture in the tube wall, and with a lifting movement will remove the prongs from the aperture.

3. A tool for removing one end of an anode lead from a cathode ray tube such as the picture tube of a television set or the like while the other end of the lead is connected to a high voltage supply, said one end of the anode lead having a two-pronged contact projecting from an insulating cover piece and adapted to extend through an orifice and be in part received in a cavity somewhat larger than the orifice in the wall of the tube, the two prongs of said contact being generally parallel and resilient, having outwardly oppositely directed retaining portions at the ends and being normally spaced from each other sufiiciently to require flexing toward one another to remove the retaining portions from the aperture and cavity, said tool comprising an insulating handle portion to facilitate grasping the tool, a rod portion carried by and extending the handle, terminating in a curved, blunt end, a flexible electrically conductive lead attached to said rod portion and connected therewith for electrical conduction, an electrically conductive spring clip attached and connected for eletrical conduction to said lead, and a relatively thin, substantially flat, prong-compressor portion attached to and adjacent the end of said rod portion opposite from the handle portion, said curved end being located substantially as far from the handle portion as the prong-compressor portion, said prong-compressor portion having a notch in an edge thereof opening in a direction away from the handle, sides of said notch converging in a direction inwardly of said edge from a spacing greater than the spacing between the two prongs of said contact when the contact is located in said orifice to a spacing at least as small as the lateral spacing to which the prongs must be moved to remove the retaining portions of the prongs from the cavity in the tube side wall, whereby the prong-compressor portion can be inserted between the tube wall and the insulating cover piece to receive the prongs of said contact within the notch by movement of the tool axially of the rod portion, with further movement in the same direction the prong-compressor portion will slide relative to the prongs to compress the resilient prongs to a spacing sufliciently close that the retaining portions can pass through the aperture in the tube wall, and with a lifting movement will remove the prongs from the aperture.

References Cited UNITED STATES PATENTS D. 55,792 7/ 1920 Hudgins 29-270 UX 1,589,683 6/1926 Clinger 29-278 X 2,613,562 10/1952 Clark 29270 X 2,736,088 2/ 1956 Thygeson 29270 3,380,141 4/1968 Rofer 29-203 H 3,461,533 8/1969 Anhalt 29-203 H GRANVILLE Y. CUS'FER, JR., Primary Examiner US. Cl. X.R.

29270; 81-3; 50; 174-5 SG; 2l9--234; 324- 72.5 

